Overview of Billing Modes

DSC provides two billing modes: yearly/monthly and pay-per-use.

Yearly/Monthly billing: A prepaid mode in which you pay for the service before using it. Your bill is settled based on the required period. The longer you use the service, the more discounts you get. This mode is applicable to mature services that have long-term and stable device requirements.
Pay-per-use billing: a postpaid mode in which you pay for what you used. You are billed by second based on the actual usage. Your bill is settled by the hour. With the pay-per-use billing mode, you can easily adapt to resource requirement changes, reducing the risk of overprovisioning of resources or lacking capacity. In this mode, there are no upfront commitments required.
Table 1 describes the differences between the billing modes.

**Table 1** Billing modes
Billing Mode	Yearly/Monthly Billing	Pay-Per-Use
Payment Method	Prepaid Billed by the purchase period specified in your order	Postpaid You are charged based on the actual number of API calls. Each month, you can make 1 million API calls. Note that the unused API calls for the previous month will become invalid.
Billing Period	Billed by the purchase period specified in the order	API calls
Billing Item	Version specifications, database extension package, and OBS extension package.	API calls (data masking and watermarking)
Changing Specifications	Version specifications can be changed.	Version specifications cannot be changed.
Application Scenario	This billing mode is cost-effective and suitable when the duration of resource usage is predictable. The yearly/monthly mode is recommended for long-term users.	This mode is ideal when you want more flexibility and control on ECS usage.